SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '69cdae10d10f996cc87065d6e3cf06961b8886eedb5cecacc94b7875de91722b' 
  AND token = '4rAZKvhievzdH9/2K4AewIuTMzMosG8YEgPsqxwhGpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}